Enhanced photocatalytic performance of Co3(PO4)2/Ag3PO4 immobilized on SiC: The synergistic effects and mechanism

Co3(PO4)2/Ag3PO4 (CoPi/AgP) were immobilized onto SiC nanowires through co-precipitation. Compared with Ag3PO4, the photoactivity and photostability of CoPi/AgP/SiC were significantly enhanced, while the cost was reduced because of the low demand for expensive Ag3PO4. Under visible light, Ag3PO4/SiC loaded with 0.5%Co3(PO4)2 achieved an apparent methyl orange (MO) degradation rate constant of 1.77 times higher than Ag3PO4 and 7.49 times higher than Ag3PO4/SiC. Moreover, after five reuses, Ag3PO4/SiC loaded with 0.5%Co3(PO4)2 maintained its photocatalytic activity at 87%, whereas pure Ag3PO4 retained only 32.5%. The synergistic action of the Z-scheme Ag3PO4/SiC heterojunction and Co3(PO4)2 cocatalyst led to enhanced photoactivity and stability. The weak internal electric field induced in Co3(PO4)2/Ag3PO4 significantly in-creased the intensity of the main internal electric field in Ag3PO4/SiC, resulting in a rapid interfacial transfer, prolonged lifetime, and strong redox ability of the photoinduced charge carriers. This mechanism de-monstrates a positive effect on charge separation, oxidative reaction kinetics, and the formation of & BULL;OH of the Co3(PO4)2 hole cocatalyst. Density functional theory (DFT) calculations and active species trapping experiments confirmed the Z-scheme electron transfer pathway. Consequently, this study provides a low-cost method to construct a novel immobilized photocatalyst with high activity and stability for the efficient degradation of organic pollutants under visible light.& COPY; 2023 Elsevier B.V. All rights reserved.

Automated summary

Co3(PO4)2/Ag3PO4 (CoPi/AgP) was immobilized onto SiC nanowires through co-precipitation. The photoactivity and photostability of CoPi/AgP/SiC were significantly enhanced compared to Ag3PO4, while reducing the cost due to the low demand for expensive Ag3PO4. Under visible light, Ag3PO4/SiC loaded with 0.5%Co3(PO4)2 achieved a higher degradation rate of methyl orange (MO) compared to Ag3PO4 and Ag3PO4/SiC. The synergistic action of the Z-scheme Ag3PO4/SiC heterojunction and Co3(PO4)2 cocatalyst led to enhanced photoactivity and stability.